If you've ever Googled "how to tell if a crystal is real," you've probably encountered the same advice on forums, TikTok, and social media posts. Some tips sound convincing. Some seem super scientific. Others come across as secrets known only to "true experts."
However -- most of them are wrong.
Below are three of the most popular crystal authenticity tests — and an explanation of why none of them actually work.
1. The Fire Test
People say you can check authenticity easily with a lighter or flame: "If it melts, produces black smoke, or smells like plastic, it's fake."
At first glance, it seems logical. Hold the crystal to a flame -- if it melts or smokes, it's fake. If not, it's genuine. But this logic fails for several reasons.
Many fake crystals are made from glass or other highly stable materials. Glass won't melt when exposed to a flame and won't give off a plastic smell, so you might think the crystal is real when it isn't.
On the other hand, many genuine crystals are coated with a protective resin layer. This is especially true for pendants made from raw crystals or more delicate minerals. The resin protects them and provides stability. If you burn it off, yes, it will disappear — but the crystal will become vulnerable to damage.
This happened to one of our customers. She tested a pendant she had just bought. The flame melted the protective resin, but underneath was a genuine crystal. Without protection, it became more fragile and exposed to external factors, making it more likely to chip or alter its constitution.
Some crystals, like selenite and celestite, are naturally sensitive. Even without resin, flame can discolor, crack, or permanently damage them. Heating genuine crystals can also risk minor explosions, especially if they contain microscopic water bubbles.
This test proves nothing and often destroys crystals that were actually genuine.
2. The Scratch Test
People say: "If it doesn't scratch glass, it's fake."
Or: "If glass can scratch it, it's fake."
This myth comes from the Mohs hardness scale, which rates minerals from 1 to 10. Quartz, a very common crystal, has a hardness of 7. Regular glass rates around 5.5. Therefore, quartz should scratch glass, but glass shouldn't scratch quartz.
This is true -- for quartz. But most crystals don't have the same hardness as quartz.
Fluorite has a hardness of 4. Calcite and celestite have a hardness of 3. Selenite only 2. All of these are natural minerals, all softer than glass. This means they won't scratch glass, and if you rub glass against these minerals, you'll definitely damage the crystal's surface. By this logic, you might wrongly conclude a genuine crystal is fake.
Some people use a knife for testing, which can cause even more damage. You might scratch, break, or create micro-cracks in the crystal that only show up later. Even if the crystal "passes" the test, you often damage it in the process.
Each mineral has its own hardness, making this test far from reliable.
3. The Cold Touch Test
People say: "If it feels cold to the touch, it's a real crystal. If it's warm, it's fake."
This test is popular because it's simple and doesn't damage the crystal. It also sounds fairly logical. Crystals often do feel colder than plastic because they conduct heat differently.
But glass gives the same cold sensation. And many fakes are made from glass.
Temperature can also be misleading. If a crystal sits in sunlight, in a warm room, or in your pocket, it will be warm. If you place it by a drafty window, under air conditioning, or in a cold room, it will be cold. Temperature has nothing to do with authenticity.
Crystals are incredibly diverse -- some have smooth surfaces, others are raw, and some are stabilized or protected with coatings. All these factors affect the temperature you feel when touching them.
If you rely on temperature, you're guessing. Not testing.
How to Actually Avoid Fakes?
These three tests don't work because each tries to apply one rule to many different types of crystals. These theories assume all fakes are soft plastic and all genuine crystals are hard, cold, and unprocessed.
But crystals aren't all the same.
If you want to avoid fakes, research each mineral that interests you before buying. Ask the seller about its origin. Look for imperfections, natural color variations, or texture. And buy from people who can answer these questions.
Don't destroy a crystal to prove it's real. There are better ways. And better sellers.
